Cancer is caused by dysregulations of signal transduction pathways. One such pathway is the Hedgehog (HH) signal transduction pathway, which involves the Patch (Ptch) and Smoothened (SMO) proteins. The HH pathway is essential for embryonic cell growth (Beachy et al., Nature, 432: 324-331 (2004)) and was found to be dysregulated in several cancers, including breast cancer (Katano et al., Cancer Lett., 227: 99-104 (2005)), prostate cancer (Sanchez et al., Proc. Natl. Acad. Sci. U.S.A., 101: 12561-12566 (2004)), stomach cancer (Berman et al., Nature, 425: 846-851 (2003)), colon cancer (Douard et al., Surgery, 139: 665-670 (2006)), liver cancer (Sicklick et al., Carcinogenesis, 27: 748-757 (2006)), melanoma (Pons et al., Clin. Transl. Oncol., 8: 466-474 (2006)), basal cell carcinoma (Lam et al., Oncogene, 18, 833-836 (1999)), and medulloblastoma (Berman et al., Science, 297, 1559-1561 (2002) and Romer et al., Cancer Res., 65, 4975-4978 (2005)). There is a desire for inhibitors of the HH pathway for use in treatment of cancers.